Fix the Outside Air Temperature (OAT) on the 2022 Africa Twin Adventure Sport
The outside air temperature display reading in the top right of the main console was always wrong when out riding the bike. I live right where the mountains start in Colorado. It can be 95f down in Denver and in the 70’s a half hour west in the mountains. The temps were usually 10 degrees warm and slow to respond to temperature changes. The temp read correctly when the bike had been sitting overnight. The sensor is located under the right side fairing screwed to the inside of the tank front cover (inner shroud). It's fully enclosed and gets no outside air flow. That's why when the bike had been sitting overnight in the garage the air under the fairing becomes ambient temperature. When the engine is running, heat from the engine and radiator rises up through the center of the bike around the forks heating up the trapped air inside of the fairing causing higher air temperature readings.
Earlier in the year I saw a YouTube video showing experiments with the air sensor. They ended up saying that things improved when they drilled a hole in the inner shroud and mounted the sensor sticking through the hole. The idea was this would expose the temperature sensor to outside air. I used this as a starting point for my experiments.
I waited until this winter when I would have some down time. I removed the right side crash bars, driving light and cowling which alone was a time consuming project. This exposed the back side of the temperature sensor and the wiring harness connector. From the inside I drilled a hole in the tank front cover which exposed the temperature sensor to outside air. After putting the whole thing together I went out for a ride and the problem was no better. That's when I realized that the air from the engine and radiator was rising up the center of the bike warming the sensor.
My next plan was to move the sensor out from under the shroud and mount it outside under the front of the headlight roughly where the sensor was located on my old KTM 1290. This would require extending the sensor wire about 12” and fishing the sensor out from under the cowl. This is a 2 wire Resistance Temperature Detector (RTD) device that reads 4.1 to 5.9k ohms. There is no problem extending the wire on this kind of sensor.
I didn't want to take the whole bike apart again. What I did was remove what Honda calls the Front Side Plate which is the metal trim with the Honda emblem, screwed into the side cowling. This exposes a good part of the area underneath the cowl. From this opening you can get to the connector where the air sensor plugs into the harness.
The trick was to get to the phillips screw holding the sensor in because it was buried behind the plastic of the inner cover. Since I already knew where the sensor was (the hole I drilled) I was able to cut a hole in the plastic from the outside of the inner cowl above the air sensor using a Dremel 561 rotary cutter. This let me get a screwdriver on the sensor screw. Once the screw was out I was able to pull the sensor in its housing out from the side plate opening.
Before I cut the sensor wire I decided to run a test with the sensor hanging out the side of the bike through the front side plate. With the sensor housing removed I pulled the sensor outside the front of the opening for the front side plate. I was able to tighten down the rear 2 screws of the side plate. I took the bike for a ride and the sensor seemed to work the way it should.
I cut the sensor wire about 1-1/2” behind the sensor and soldered on a 12" extension. I insulated everything with shrink tubing. I carefully fished the sensor (housing removed) from the inside of the cowl through the hole I already had in the inner cover. I pulled out about 8” of wire. I replaced the sensor housing and routed it down under the headlight and wire tied it to my upper crash bar bracket.
Now the moment of truth. I took a ride where the temps were in the low 60's (nice for December in Colorado) and then went into the mountain canyons where the temps went up and down depending if you're in the shade or not. The temps were all reasonable and fluctuated up and down between 42f and 56f in the canyon and back to 62f out in the sun on the highway. When I stopped for gas, heat rising from the bike caused temps to rise 5 to 10 degrees f due to heat rising from the engine. When I got rolling again the temps came right back to normal. I went out riding with some friends and checked my temp readings against theirs and they matched.
If I had it to do again I could do it without having to remove the whole side cowl and crash bar. I’d just use the Dremel cutter to remove the plastic covering the phillips sensor mounting screw. The only thing I want to do is to seal up the hole I drilled in the tank front cover to keep junk from getting behind the cowl.
